A system for descaling apparatus is described. The system provides for: a water inlet feedstream; a reverse osmosis system in fluid communication with the water inlet feedstream, in which the reverse osmosis system produces a water permeate output feedstream; and a pressurised carbon dioxide feedstream. The pressurised carbon dioxide feedstream and water permeate output feedstream are arranged in use to combine to produce a pressurised carbonic acid input feedstream.

The present invention provides a cleaning agent for aromatic polyamide reverse osmosis membranes, the cleaning agent being composed of an aqueous solution which has a pH of 13 or more and contains a stabilized halogen, a chelating agent that contains one or more substances selected from among aliphatic carboxylic acids containing no amino group, phosphonic acid compounds containing no amino group, polyphosphoric acids, and salts thereof, and an alkaline agent. According to the present invention, an aromatic polyamide reverse osmosis membrane is cleaned with use of a cleaning liquid that is composed of an aqueous solution of this cleaning agent. A chloramine compound which is obtained by mixing a compound having a primary amino group with hypochlorous acid and/or a hypochlorite is suitable for use as the stabilized halogen.

A subsea water processing system and associated methods are disclosed. The subsea water processing system includes a microfiltration unit, an ultrafiltration unit, and an electrochemical unit. The microfiltration unit includes an oil-tolerant microfiltration membrane and is configured to receive a stream of produced water and to produce a first treated stream of water. The ultrafiltration unit is fluidly connected downstream of the microfiltration unit, includes an oil-rejecting ultrafiltration membrane, and is configured to receive the first treated stream of water and to produce a second treated stream of water. The electrochemical unit is fluidly connected to at least one of the microfiltration unit or the ultrafiltration unit, and is configured to produce an acid and a base, and to deliver the acid, the base, or both the acid and the base to the at least one of the microfiltration unit or the ultrafiltration unit during a cleaning cycle.

This invention relates to a system for continuously dehumidifying humid gas. More particularly, this invention relates to a system that continuously dehumidifies gas using a liquid desiccant dehumidifying module, a regeneration modules utilizing a membrane distillation module to regenerate diluted liquid desiccant and means for connecting the two modules together.

A cleaning method for a water treatment membrane (2) provided with a primary surface (2a) for inflow of untreated water and a secondary' surface (2b) for outflow of treated water, the method including a first cleaning step of bringing a first cleaning fluid containing a metal eluent into contact with at least the primary surface and eliminating metallic scale (11) attached to the water treatment membrane, and then a second cleaning step for bringing a second cleaning fluid containing an oxidizing agent into contact with at least the primary surface and eliminating organic scale (12) attached to the water treatment membrane.

A method of producing purified water in a subsurface environment is provided in which ambient subsurface source water is introduced into and through one or more ultrafiltration membrane units of a subsurface water treatment system and producing thereby an ultrafiltrate substantially free of solid particulates having a largest dimension greater than 0.1 microns. An electrochemical unit in fluid communication with at least one ultrafiltration membrane unit provides an antifoulant solution. An ultrafiltrate-rich backwash fluid and at least a portion of the antifoulant solution are delivered to at least one non-producing ultrafiltration membrane unit during a backwash cycle. A flux of source fluid through each of the ultrafiltration membrane units of less than thirty gallons per square foot per day limits the need for backwash cycles. A reduction in the number of backwash cycles enhances system autonomy and useful life, and limits the need for intervention for maintenance and component replacement.

A method of producing a sugar liquid includes filtering a cellulose-derived sugar liquid through one or more separation membranes selected from the group consisting of an ultrafiltration membrane, a nanofiltration membrane and a reverse osmosis membrane, and washing the separation membrane(s) after filtration with washing water containing an acidic substance and an aromatic compound.

The present disclosure relates to biocide compositions, formulations and methods for using formulations. In particular the present disclosure relates to biocide compositions and their use in treating reverse osmosis membranes.

A method and a composition of cleaning and reprocessing a hemodialysis filtration membrane assembly that employs polyvinylpyrrolidone-containing membranes, the method comprising the step of treating the assembly with an aqueous mixture or a gas-liquid mixture comprising an inorganic base and from 100 to 1,000 ppm of a hypochlorite salt, wherein the mixture has a pH between about 12.0 and about 12.5, an oxidation reduction potential of less than 0.5 volts, a temperature of 40 to 55 C. and wherein the mole % of hypochlorous acid, HOCl, relative to the sum of hypochlorous acid plus hypochlorite anion, OCl, is less than 0.004%.

Ozonated washing water is generated by injecting an ozone gas into pressurized washing water that is filtered water obtained by membrane filtration of untreated water and that is to be used at the time of backwashing, and the ozonated washing water is supplied to a membrane from the filtration secondary side to thereby remove a fouling substance inside the membrane, while causing ozone-containing bubbles to emerge in the filtration primary side to thereby remove a fouling substance on a membrane surface in the filtration primary side.